- Sprung Mass (everything supported by the springs) The vehicle masses that are supported by the vehicle springs. Sprung weight moves “indirectly” with the road surface. Body, passengers, parts of drive train, and parts of suspension.
- Unsprung Mass (everything between the springs and the road surface) The vehicle masses that are directly driven by tire input forces. Unsprung weight moves “directly” with the road surface. Wheels, tires, brakes, some suspension etc.